1. Field of the Invention
The present invention relates to a technique of extracting a specific object in a motion picture, and more particularly to an object extracting method using motion pictures which more accurately and rapidly extracts an object using information of a moving object in a motion picture and color information which defines a color of the object.
2. Description of the Conventional Art
A motion picture is composed of image frames, each frame carries information with respect to an object. Recently, a conventional technique which extracts a specific object using the motion picture can be divided into two ways; one is to extract the object using only color information which defines a color thereof and the other is to extract the object using information of motion changes of the object.
First, the conventional object extracting method using the color information will be explained.
After obtaining a still image frame from a motion picture, a preprocessing step is performed, which generates a color histogram by converting a negative image of the still image frame to a positive image.
Next, red, green and blue (RGB) color domains included in the histogram are converted to hue saturation values (HSV), and color information of the object such as skin-color pixels are obtained. To the color pixels, segmentation occurs through edge detection, hole filtering and gap filtering. Finally, the segments and a predetermined object domain are compared, thus the specific object is extracted.
However, because the conventional object extracting method using only the color information obtains one still image frame using the color information which defines the color of the object and thus extracts the object therefrom, the object may not be accurately obtained. Accordingly, the above object extracting method using the color information requires a considerable operation time to extract the object because RGB color space is converted to HSV color space with respect to the inaccurate object domain.
A face-it method which is the other object extracting method extracts a specific object only using motion information of the object on a motion picture, without using color information thereof. Particularly, the face-it method which extracts a human face designates an area in which there is a movement of a specific object as a face domain candidate and carries out a grey image process for the domain candidate, thereby obtaining information with respect to the corresponding human face. Accordingly, the face-it which extracts the human face with insufficient information has difficulty of accurately extracting a human face.